Chile on Monday filed a lawsuit against neighbor Bolivia at the U.N.'s highest court in The Hague, seeking a ruling in their decades-old dispute over whether Chile has the right to use a river that crosses their shared border.
Chilean officials submitted documentation to start formal legal proceedings over the Silala River, asking the International Court of Justice to declare it "an international watercourse" and granting Chile usage rights.
Chile uses some of river water in its parched Atacama Desert to feed mine operations. Bolivia wants to charge Santiago for it, claiming ownership of the Silala on the grounds that it originates from springs on its side of the border.
"Bolivia's statements [on the matter] have forced Chile to act in self-defense of its rights, which are being contested in a hostile manner," said Chile's Foreign Minister, Heraldo Munoz.
The South American neighbors have been engaged in a separate legal case at the court since 2013, when landlocked Bolivia filed proceedings demanding that Chile grant it access to the Pacific Ocean.
"Unlike the legal suit brought forth by Bolivia in 2013, this action by Chile is based on a genuine judicial and technical dispute, which seeks the International Court of Justice to declare and confirm what Bolivia is trying to deny, that the Silala is an international watercourse," added Munoz.
The United Nations Environmental Program has called the Silala one of the most vulnerable water basins in the world "because of the underlying issues of politics, economics, sovereignty and history."
As desertification and access to water become increasingly relevant, the case will be closely watched by other nations in similar disputes over scarce natural resources.